How could we survive on Mars?

An astronaut is stuck on Mars. Will he come out of it alive? It's the thought in everyone's head after seeing trailers for upcoming space survival film The Martian. But what would it take for us to actually survive on the Red Planet?

This year's futuristic sci-fi blockbuster by Ridley Scott tells the story of an astronaut who accidentally gets stranded on Mars. Based on a best-selling book by American author Andy Weir, The Martian has audiences excited thanks to its realism and scientific accuracy.

Dr Phil Metzger is a planetary physicist at the University of Central Florida, who’s spent nearly 30 years at NASA’s Kennedy Space Center.

“When the book first came out, the word about it got around within NASA. I worked in the community of people that were developing technologies for living off the land, and there was quite a buzz, people talking about this book because it was super cool, it was actually doing the things that we were working on, and the book got it right.”

Mars is extremely cold, dusty, and we can’t breathe on its surface. It would take about six months to get there, with light luggage because every gram costs precious fuel.

Historian Guy Murphy, author of Mars: A Survival Guide explains the benefits of the Red Planet.

“We see in the landscape of Mars a place where we intuitively understand people could potentially live and settle, and one of the things that's different about Mars from, say, the Moon or from other places in the solar system, is that all the resources humans need to survive are actually there, accessible on the surface.”

This includes minerals and chemical ingredients for making breathable air. But Phil Metzger says we still need to invent the technology - something NASA’s working on.

“We're aiming to get to Mars by the 2030s, and if we keep plugging away at it we will do that. It's going to take us a good 10 or 15 years to go through that process to develop all the different tools we need to live on Mars.”

“Right now we think that an astronaut could do one short Mars mission and then come back home, but the radiation dose would be so high that she would not be able to do any other space missions for the rest of her life.”

“We know how to do it - you can simply use dirt and just pile up dirt on the top of the habitat, but in order to make it stable so that it doesn't collapse your habitat, you probably want to turn the dirt into concrete and build structures with it.”

Humans also need to stay warm and breathe air. All of these things on Mars need to be created from scratch, using energy such as solar power.

Guy Murphy lists the day-to-day problems.

“Thinking about the challenges, the key things you got to have to survive are pressurised habitat, including space suits, temperature control and energy sources, and access to food and water.”

There's a lot of water on Mars - it’s in the soil, and frozen under the surface. This week NASA announced there’s evidence of salty liquid water flowing on the Martian surface on warmer months.

According to Dr Metzger, we probably can't drink the water up there.

“We've recently discovered that the Martian soil contains perchlorates which are poisonous to humans, and so we would need to verify that the water clean-up technologies are able to remove the perchlorates and remove any other chemistry that we don't know about yet.”

But if nothing grows on Mars - where would we get food?

“We're working right now on growing food in low gravity, and figuring out ways to use different wavelengths of light to minimise the energy cost of growing food; in the story they didn't originally plan to grow food on Mars so that was one of the things that Mark Watney had to solve on his own.”

But why are we trying to get to Mars if it's so difficult? A thirst for exploration is in human nature. But we also learn a lot from exploring space.

NASA scientist John Grunsfeld believes by studying Mars we can learn about our planet.

"From the Curiosity rover, we now know that Mars once was a planet very much like Earth, with warm, salty seas, with freshwater lakes, probably snow-capped peaks and clouds and a water cycle, just like we're studying here on Earth with our earth-science satellites, the water cycle here on Earth. But something has happened to Mars. It lost its water. But we still have -- in the atmosphere and on the surface, for the most part, but we still have -- the question of, 'Did life arise on Mars once, and can we find out?''"

If we ever found life on Mars, it would change how we understand the universe.

Dr Metzger says colonising Mars could also have a role in ensuring humanity’s survival.

“So there's planetary science, there's life; and then there's also the idea of spreading humanity beyond planet Earth in order to secure our place in the universe. If we had a long-period comet come in and whack the Earth, it could wipe out all life on the Earth within the next couple years. It's extremely unlikely, but the consequences of that are so unspeakably horrible that it's still worth doing something about it.”

So are we going to live on Mars one day?

Guy Murphy thinks it will happen.

“I think with time there will be a permanent population there, and in the longer term, maybe within a century or two, a self-sustaining population, but I think it will happen. There is a deep human instinct to spread a human presence to different places. The first missions will inevitably be quite dangerous, but I think it would be quite a wondrous thing to visit a completely new, unexplored planet. It's a completely unspoilt world.”

Dr Metzger thinks we need to start by mining asteroids and developing manufacturing in space, to get enough resources. Then we could have a chance to stay on the Red Planet.

“We are looking forward to doing some sortee missions in the 2030s and those missions, when we put the first humans on Mars, similar to what you see in the book and soon what we'll see in the movie, those missions are going to revolutionise our understanding of Mars, just like the Apollo missions revolutionised our understanding of the Moon.”